[BUGFIX] Add `config.contentObjectExceptionHandler` to tsref.xml

The TypoScript setting `config.contentObjectExceptionHandler` was
introduced in TYPO3 7.0 but is still missing in tsref.xml. This patch
adds the configuration.

Resolves: #81093
Releases: master, 8.7, 7.6
Change-Id: Ib46891699aca91329aef302d87e562ac317892f2
Reviewed-on: https://review.typo3.org/52667


Reviewed-by: Henrik Elsner <helsner@dfau.de>
Tested-by: Henrik Elsner <helsner@dfau.de>
Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Tymoteusz Motylewski <t.motylewski@gmail.com>
Tested-by: Tymoteusz Motylewski <t.motylewski@gmail.com>